Fuel And Oil Detergents

ABSTRACT

This invention is directed to lubricating compositions which contain detergent-dispersant components derived from substantially linear alkylbenzenes including sulfonates, overbased sulfonates, and salts and esters thereof. Detergents provided by the invention have a low content of the 1-aryl isomers than materials of prior art. In addition, the detergents of the present invention are prepared using alkylbenzene mixtures which have substantially-reduced benzene content over materials provided by the prior art. The invention provides compositions which are useful in formulating lubricants, motor oils, and the like.

TECHNICAL FIELD

This invention relates to a oil-soluble compositions of matter useful asdetergent components in hydrocarbon oils useful for a wide range ofpurposes, including without limitation general lubricants, lubricatingoils for internal combustion engines, cutting fluids, emulsions, anddispersions.

More particularly, the invention relates to oil-soluble alkylbenzenescomprising alkyl chains having between about 16 and 30 carbon atoms inwhich the alkylbenzenes have a low dialkylate content and unique isomerdistribution, including their sulfonate and other water-soluble andsolubilizable derivatives.

BACKGROUND

The chemical structure and use of linear alkylbenzenes and theirderivatives, including their sulfonate derivatives, in the manufactureof laundry detergents is well known. Generally, linear alkylbenzenes areproduced by an alkylation reaction (according to one of any well knownprocesses for producing such materials) in which the net result is theappendage of a hydrocarbyl radical to a benzene ring. The source of thehydrocarbyl radical may be a branched or a linear olefin, either aninternal olefin or an alpha olefin, and in practice a mixture ofsubstantially linear olefins is typically used, which mixture comprisesvarious olefins having different numbers of carbon atoms per molecule.For the manufacture of laundry detergents, the range of carbon numbers(the number of carbon atoms per molecule of an olefin used) of an olefinmixture used in the alkylation reaction is typically in the range ofbetween about 8 and 15 (inclusive) carbon atoms per molecule, whichmolecules are sometimes collectively referred to by those in the art asthe “detergent range”.

Alkylation of benzene using olefins in the detergent range leads to areaction product mixture which contains alkylated benzenes havinghydrocarbyl radicals of different chain length appended to a benzeneYing, and also contains position isomers of these alkylation products.Thus, a reaction mixture from the alkylation of benzene using detergentrange olefins is often complex in makeup.

Of the possible position isomers referred to above, it has been recentlydiscovered that detergents for use in aqueous systems, which areprepared from alkylbenzenes having the benzene ring located at the2-position on the hydrocarbyl radical possess enhanced detergency andother beneficial properties over the other isomers produced in thealkylation. This is believed in part to be true because the hydrocarbonchain that is appended to the ring extends a greater distance in spacein isomers having a phenyl group in the 2-position than the otherposition isomers, thus providing a molecule having a more volumetricallyexposed hydrocarbon chain portion over other position isomers. Amongother things, this increased exposure provides increased availabilityfor interaction with hydrophobic materials which are sought to besolubilized in an aqueous medium, when the alkylbenzene also includes ahydrophilic moiety, such as a sulfonate group bonded to the benzenering.

Detergents useful as components in hydrocarbon oils are often possessivein general of the same properties as detergents useful in aqueous media,that is, their molecules contain both a hydrophilic and a hydrophobicportion. However, in many applications it may be beneficial to employalkylbenzenes having longer hydrocarbon chains on the benzene ring thanthose found in conventional detergents, for example to enhancesolubility in hydrocarbon oils, or to provide increased compatibilityand chemical inertness with respect to other components of theformulation, depending upon the intended use.

The production of sulfonates by reaction with, e.g., SO₃, is well knownto those skilled in the art. See, for example, the article “Sulfonates”in Kirk-Othmer “Encyclopedia of Chemical Technology”, Second Edition,Vol. 19, pp. 291 et seq. published by John Wiley & Sons, N.Y. (1969).Other descriptions of neutral and basic sulfonate salts and techniquesfor making them can be found in the following U.S. Pat. Nos. 2,174,110;2,174,506; 2,174,508; 2,193,824; 2,197,800; 2,202,781; 2,212,786;2,213,360; 2,228,598; 2,223,676; 2,239,974; 2,263,312; 2,276,090;2,276,097; 2,315,514; 2,319,121; 2,321,022; 2,333,568; 2,333,788;2,335,259; 2,337,552; 2,347,568; 2,366,027; 2,374,193; 2,383,319;3,312,618; 3,471,403; 3,488,284; 3,595,790; and 3,798,012. These and allother patents, books, excerpts, articles, and literature cited hereinare fully incorporated by reference.

Although the prior art is replete with prior art concerning the use ofalkylbenzene based detergents in hydrocarbon based oils such as motoroils, hydraulic fluids, cuffing fluids, etc., none have thus farprovided commercially quantities of an alkylbenzene based detergentcomponent in which the hydrocarbon tails of the molecule have carbonnumbers of any integral value in the range of between about 16 and 30carbon atoms per molecule, in which the 2-phenyl isomer content is inthe range of between about 10% and 13%. We have recognized that a needexists for a method of linear alkylbenzene (“LAB”) production havinghigh substrate olefin conversion, controlled selectivity to 2-phenylisomer LAB, and employing a catalyst having long lifetimes and easyhandling, by which controllable 2-phenyl isomer content and lowdialkylate content can be achieved in materials having relatively longhydrocarbon tails attached to a benzene ring in a linear alkylbenzenebased detergent.

The present invention employs hydrogen fluoride as a catalyst in theproduction of long-tail linear alkylbenzenes. The processing conditionsused in preparing the materials of this invention may in one form of theinvention provide essentially any desired percentage content of 2-phenylisomer in the range of about 8 to about 27% (on a weight basis) in thefinished product by adjusting the processing parameters. In this way,LAB may be produced having any desired 2-phenyl isomer content in therange of about 10% to 13% by weight based on the total weight of thealkylbenzene.

This invention, in one broad respect, is a process for the production oflinear alkylbenzenes which comprises contacting benzene and an olefinhaving about 8 to about 30 carbons in the presence of an effectivecatalytic amount of hydrogen fluoride to form linear alkylbenzenes,wherein the isomerization of the olefins is conducted in the sameprocess step as the alkylation of benzene

In another broad respect, this invention is a process for the productionof oil-soluble alkylbenzene sulfonates suitable for use in fluids usedin the transportation industry, including without limitation, additivesfor passenger car engine oils, additives for diesel engine oils,driveline lubricants, transmission fluids, or any other application inwhich an oil-soluble sulfonate salt or an overbased sulfonate confers abeneficial property to the performance of the lubricant.

For whatever reason, the alkylbenzenes within the prior art which aresold as a raw material from which overbased sulfonates may be preparedall contain benzene at a level of between about 3 and 10 parts permillion. Benzene is notorious for causing leukemia. The presentinvention provides alkylbenzenes from which overbased alkaline earthmetal sulfonates may be prepared in which benzene is present at a levelof less than 100 parts per billion.

In addition, the materials of the prior art all contain significantlevels of 1-phenyl (1-aryl) isomer. According to this invention, the1-phenyl (1-aryl) content is negligible, being less than 0.3% by weightbased on the total weight of all alkylaryl isomers present in a mixtureof the invention.

SUMMARY OF THE INVENTION

The present invention provides a process for production of alkylaromaticcompounds which comprises the steps of:

-   -   a) co-mingling linear alpha olefins, having 16 to 40 carbon        atoms per molecule, with a non-reactive diluent, such as normal        or branched paraffin to form a mixture of alpha olefins and        paraffins;    -   b) feeding the mixture of alpha olefins and paraffins into a        reaction zone along with a feed aromatic hydrocarbon and liquid        hydrogen fluoride, under alkylation-promoting conditions, to        produce an effluent stream containing the feed aromatic        hydrocarbon, hydrogen fluoride, paraffin, and alkylaromatic        hydrocarbon product;    -   c) separating substantially all of the hydrocarbon mixture in        the reaction zone effluent stream from the liquid phase hydrogen        fluoride present in the effluent stream; and    -   d) and recovering the product alkylaromatic hydrocarbon.        The product alkylaromatic hydrocarbon is conveniently recovered        by a series of steps involving passage of the hydrocarbon        mixture through a plurality of stripping columns to remove the        feed aromatic hydrocarbon and paraffin diluent components. The        alkylaromatic product is recovered as a net bottom stream.

In another form of the invention is provided a process for producing analkylaromatic hydrocarbon which comprises the steps of:

-   -   a) dehydrogenating a paraffin to form an olefin;    -   b) sending a feed stream of benzene and the olefin through a        conduit to a linear alkylbenzenes alkylation reactor containing        hydrogen fluoride under conditions which enable isomerization of        the olefin to occur simultaneously with alkylation of benzene by        the olefin, to form a crude linear alkylbenzenes stream;    -   c) distilling the crude linear alkylbenzenes stream in a first        distillation column to separate benzene that did not react and        to form a benzene-free linear alkylbenzenes stream;    -   d) distilling the benzene-free linear alkylbenzenes stream in a        second distillation column to separate any paraffin present and        to form a paraffin-free linear alkylbenzenes stream;    -   e) distilling the paraffin-free linear alkylbenzene stream in a        third distillation column to provide an overhead of a purified        linear alkylbenzene stream and removing a bottoms stream        containing heavies.

Certain terms and phrases have the following meanings as used herein.

“Conv.” and “Conversion” mean the mole percentage of a given reactantconverted to product. Generally, olefin conversion is about 95 percentor more in the practice of this invention.

“Sel.” and “Selectivity” mean the mole percentage of a particularcomponent in the product. Generally, selectivity to the 2-phenyl isomeris about 70% or more in the practice of this invention.

“LAB” means a mixture linear alkylbenzenes which comprises a benzenering appended to any carbon atom of a substantially linear alkyl chainhaving any number of carbon atoms in the range of 16 to 30, inclusive.Hydrogen fluoride is useful as a catalyst useful in the production ofLAB's in accordance with the process of manufacturing LAB's of thisinvention. LAB is useful as starting material to produce sulfonated LAB,which is useful as a surfactant.

“LAB sulfonates” means LAB which has been sulfonated to include anacidic sulfonate group appended to the benzene ring (thus forming a“parent acid”), and subsequently rendered to a form more soluble toaqueous solution than the parent acid by neutralization using any ofalkali metal hydroxides, alkaline earth hydroxides, ammonium hydroxides,alkylammonium hydroxides, or any chemical agent known by those skilledin the art to react with linear alkylbenzene sulfonic acids to formwater-soluble LAB sulfonates.

“Detergent range” means an olefin, alkyl group, or molecular species(including without limitation LAB, LAB sulfonates, and overbased LABsulfonates) that comprises any number of carbon atoms selected from: 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, as warrantedby the context, including mixtures of two or more such species havingdifferent numbers of carbon atoms appended to the aromatic ring.

“Substantially linear” when referring to a hydrocarbon or alkyl chainthat is part of an alkylbenzene, whether the alkylbenzene is sulfonatedor not, means a hydrocarbon comprising between 16 and 30 carbon atomslinked to one another to form a straight chain, wherein the carbon atomsof said straight chain may have only hydrogen atoms or a methyl groupbonded to them as appendages.

“Branched alkyl” when referring to a hydrocarbon or alkyl chain that ispart of an alkylbenzene, whether the alkylbenzene is sulfonated or not,means a hydrocarbon comprising between 16 and 30 carbon atoms linked toone another to form a straight chain, wherein one or more of the carbonatoms of said straight chain may have a hydrogen atom and any alkylgroup other than a methyl group (including without limitation ethylgroups), bonded to them as appendages.

“Branched alkylbenzene” means a molecular species which comprises abranched alkyl chain appended to a benzene ring.

“Branched alkylbenzene sulfonate” means a water-soluble salt of abranched alkylbenzene that has been sulfonated.

“Overbased sulfonate” means an LAB sulfonate in which an amount of anyone or more alkaline metals selected from the group consisting of Na, K,Mg, Ca, Ba, Sr are present in any amount which is greater than thestoichiometric amount of metal which would be present if the parent LABsulfonic acid, R—S(═O)(═O)OH, were fully neutralized. The exactstructure of this type compound has not been determined.

“2-phenyl alkylbenzenes” means a benzene ring having at least one alkylgroup attached to it, wherein the alkyl group comprises any number ofcarbon atoms between 16 and 30 (including every integral numbertherebetween) linked to one another so as to form a substantially linearchain and wherein the benzene ring is attached the alkyl group at acarbon atom that is adjacent to the terminal carbon of the substantiallylinear chain. Thus, the carbon atom that is attached to the benzene ringhas a methyl group and an alkyl group attached to it in a 2-phenylalkylbenzene. Thus, the 2-phenyl isomer of substantially linear LABproduced in accordance with this invention is of the formula:

in which n is any integer between about 12 and about 30; R₁, R₂, R₃, R₄,and R₅ are each independently selected from the group consisting of:hydrogen, a methyl group, an ethyl group, a propyl group, and a butylgroup; B is selected from the group consisting of: hydrogen, methyl, orethyl; B is attached to any single carbon atom along the —(CH₂)_(n)—portion of the alkyl chain; and the total 2-aryl isomer content of saidmixture of alkylbenzenes is between about 8% and about 30% by weightbased on the total weight of all alkylbenzenes present in said mixtureand in which the 1-aryl isomer content is less than about 3% by weightbased on the weight of all isomers of alkylbenzene derivatives present.

“Alkylbenzenes” means all species containing an alkyl group, whetherlinear or branched, appended to a benzene ring. Within this definitionare also embraced monoalkyltoluenes, monoalkylxylenes,alkylethylbenzenes, etc.

“Sulfonated 2-phenyl alkylbenzenes” means 2-phenyl alkylbenzenes asdefined above which further comprise a sulfonate group attached to thebenzene ring of a 2-aryl alkylbenzene, regardless of the position of thesulfonate group on the ring with respect to the location of the alkylgroup. However, it is typical, though not always the case (as in orthoisomers invariably present) for the sulfonate group to appear in theposition R₃ above with respect to a single alkyl group attached to thebenzene ring, as shown in the following structure:

in which n is any integer between about 12 and about 30; R₁, R₂, R₄, andR₅ are each independently selected from the group consisting of:hydrogen, a methyl group, an ethyl group, a propyl group, and a butylgroup; B is selected from the group consisting of: hydrogen, methyl, orethyl; B is attached to any single carbon atom along the —(CH₂)_(n)—portion of the alkyl chain; and the total 2-aryl isomer content of saidmixture of alkylbenzenes is between about 8% and about 30% by weightbased on the total weight of all alkylbenzenes present in said mixtureand in which the 1-aryl isomer content is less than about 3% by weightbased on the weight of all isomers of alkylbenzene derivatives present.

“Motor fuel” means those compositions generally recognized by those inthe art as liquid hydrocarbon fuels in the gasoline boiling range,including hydrocarbon base fuels. Within the meaning of this term isincluded those fuels often termed as “petroleum distillate fuels” bythose in the art and which have the above characteristic boiling points.The term is, however, not intended to be restricted to straight-rundistillate fractions. The distillate fuel can be straight-run distillatefuel, catalytically or thermally cracked (including hydrocracked)distillate fuel, or a mixture of straight-run distillate fuel, naphthasand the like with cracked distillate stocks. Also, the base fuels usedin the formulations of the fuel compositions of the present inventioncan be treated in accordance with well-known commercial methods such asacid or caustic treatments, hydrogen solvent refining, clay treatment,etc. Gasolines are supplied in a number of different grades dependingupon the type of service for which they are intended. The gasolinesuseful in the present invention include those designed as motor andaviation gasolines. Motor gasolines include those defined by ASTMspecification D-439-73 and are composed of a mixture of various types ofhydrocarbons including aromatics, olefins, paraffins, isoparaffins,naphthalenes, and occasionally diolefins. Motor gasolines normally havea boiling range within the limits of about 20 degrees C. to about 230degrees C., while aviation gasolines have narrower boiling ranges,usually within the limits of about 37 degrees C. to 165 degrees C. Alsowithin this definition are the kerosene range fuels, which includediesel fuels and jet fuel.

“Ashless Dispersants” means any material regarded by those in the motorfuel arts as possessive of dispersant characteristics and which uponcombustion leaves substantially no ash.

“Base Number” or “BN” refers to the amount of base equivalent tomilligrams of KOH in one gram of sample. Thus, higher BN numbers reflectmore alkaline products, and therefore a greater alkalinity reserve. TheBN of a sample can be determined by ASTM Test No. D2896 or any otherequivalent procedure.

In this specification and the appended claims, unless otherwisespecified, all percentages are in weight percent, all ratios are molarratios, and all molecular weights are number average molecular weights.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a representation of a first continuous reactivedistillation column employed in the practice of this invention.

FIG. 2 shows a representation of a second continuous reactivedistillation column employed in the practice of this invention.

FIG. 3 shows a representative process scheme for one embodiment of thisinvention where a fluorine-containing mordenite is employed with asecond, solid catalyst to achieve variable 2-phenyl isomer contentdepending on the relative proportions of the two catalysts.

DETAILED DESCRIPTION Reactants for LAB Production

In the practice of this invention, benzene or a substituted benzene suchas toluene, ethylbenzene, propylbenzene, butylbenzene, or one or morexylenes is alkylated with an olefinic material to form LAB. Olefins andbenzene can be handled and purified using standard techniques recognizedby those of ordinary skill in the art. In this regard, it is preferredthat the reactants are substantially free from hydric compounds such aswater and alcohols, etc. The olefins employed in the practice of thisinvention have from about 16 to about 30 carbons per molecule, and inone form of the invention preferably from about 20 to about 24 carbonatoms. It is most preferred that the olefinic material be a mono-olefin.It is most preferred that the mono-olefin be an alpha-olefin, in whichthe double bond is located in a terminal ethylenic unit; however,internal olefins are suitable as well, since they are isomerized in thesame step as the alkylation, in one preferred form of the invention.

Commonly, such olefins would be available from a paraffinic media of thesame carbon range. One route by which olefins in the 16 to 30 carbonnumber range are available is from dehydrogenating a mixture ofparaffins in the same carbon number range, namely C⁻¹⁶ to C⁻³⁰paraffins. Such dehydrogenation may be carried out even if such aparaffin mixture has any appreciable olefin content, for example, anolefin content in the range of about 5 to 20%. It is especiallypreferred to carry out such a process using our catalyst and processesas described in U.S. Pat. Nos. 6,417,135 and 6,700,028, both of whichare fully incorporated herein by reference thereto.

Process Conditions, Procedures, and Apparatus

The process of this invention can be carried out using the continuousreactive distillation column depicted in FIG. 1. In FIG. 1, a feedmixture of benzene and olefin, generally at a benzene-to-olefin molarratio range of about 1:1 to 100:1 flows from feed pump 10 to feed inlet14 via line 12. The feed mixture falls to a region containing hydrogenfluoride gas 32 where alkylation and isomerization occurs.Alternatively, while not depicted in FIG. 1, the benzene and olefin canbe introduced separately into the zone with mixing occurring in the HFzone, or the reactants can be mixed via an in-line mixer prior tointroducing the reactants into the catalyst zone, or the reactants canbe injected separately above the HF zone with mixing affected by use ofstandard packing above the zone, or the reactants can be sparged intothe chamber above the zone. In the catalyst zone 32, the falling feedmixture also contacts rising vapors of unreacted benzene which has beenheated to reflux in reboiler 42 by heater 40. Such rising vapors passover thermocouple 38 which monitors temperature to provide feedback toheater 40. The rising vapors of benzene and/or olefin also pass throughstandard packing 36 (e.g., 7.5 inches of goodloe packing). The risingvapors heat thermocouple 30 which connects to bottoms temperaturecontroller 28 which activates heater 40 when temperature drops below aset level.

Prior to startup, the system may be flushed with nitrogen which entersvia line 54 and which flows through line 58. After startup, a nitrogenblanket is maintained over the system. Also prior to startup and duringnitrogen flush, it may be desirable to heat catalyst zone 32 so as todrive off water. In an alternate form of the invention, HF gas may beadmitted to line 54.

Residual water from the feed mixture or which otherwise enters thesystem is collected in water trap 24 upon being liquefied at condenser21 (along with benzene vapor). If the feed is very dry (free of water)the water trap 24 may not be needed. Removing water leads to betterproduct quality. Hence, the water trap 24 is optional. The same appliesto FIG. 2. Condenser 21 is cooled via coolant such as water enteringcondenser 21 via port 22 and exiting via port 20. As needed, water inwater trap 24 may be drained by opening drain valve 26.

As needed, when LAB content in reboiler 42 rises to a desired level, thebottoms LAB product may be removed from the system via line 47, usingeither gravity or bottoms pump 48 to withdraw the product. When productis so withdrawn, valve 44 is opened.

In FIG. 1, dip tube 46, which is optional, is employed to slightlyincrease the pressure in reboiler 42 to thereby raise the boiling pointof benzene a degree or two. Likewise, a pressure generator 56 may beoptionally employed to raise the pressure of the system. Other standardpressure increasing devices can be employed. Pressure can thus beincreased in the system such that the boiling point of benzene increasesup to about 200° C.

In FIG. 1, control mechanisms for heat shutoff 50 and pump shutoff 52are depicted which serve to shut off heat and pump if the liquids levelin the system rises to such levels. These control mechanisms areoptional and may be included so that the catalyst zone does not comeinto contact with the bottoms of the reboiler.

In the practice of this invention in the alkylation of benzene, a widevariety of process conditions can be employed. In this regard, thetemperature in the catalyst zone may vary depending on reactants, rateof introduction into the catalyst zone, size of the catalyst zone, andso forth. Generally, the zone is maintained at the reflux temperature ofbenzene depending on pressure. Typically, the temperature of thecatalyst zone is above about 70° C., and most likely about 78° C. ormore in order to have reasonable reaction rates, and about 200° C. orless to avoid degradation of reactants and products and to avoid cokebuild-up in the catalyst zone. Preferably, the temperature is in therange from about 80° C. to about 140° C. The process may be operated ata variety of pressures during the contact of HF with the reactants, withpressures of about atmospheric most typically being employed. When theprocess is operated using a system as depicted in FIGS. 1 and 2, thereboiler temperature is maintained such that benzene and olefinvaporize, the temperature varying depending on olefin, and generallybeing from about 80° C. to about 250° C. for olefins having 16 to 24carbons. The composition of the reboiler will vary over time, but isgenerally set initially to have a benzene olefin ratio of about 10:1,with this ratio being maintained during the practice of this invention.The rate of introduction of feed into the catalyst zone may vary, and isgenerally at a liquid hourly space velocity (“LHSV”) of about 0.05 hr⁻¹to about 10 hr⁻¹, more typically from about 0.05 hr⁻¹ to about 1 hr⁻¹.The mole ratio of benzene to olefin introduced into the catalyst zone isgenerally from about 1:1 to about 100:1. In commercial benzenealkylation operations, it is common to run at mole ratios of from about2:1 to about 20:1, which can suitably be employed in the practice ofthis invention, and to charge said olefins as an olefin-paraffin mixturecomprising 5% to 20% olefin content. Said olefin-paraffin mixtures arenormally generated commercially through dehydrogenation of thecorresponding paraffin starting material over a noble metal catalyst aspreviously specified.

Another continuous reactive distillation apparatus is depicted in FIG.2. In FIG. 2, the feed mixture enters the reactor via feed inlet 114.The feed mixture falls through the column into catalyst zone 132,wherein alkylation to form LAB occurs. A thermowell 133 monitors thetemperature of said catalyst zone 132. The catalyst zone 132 may beoptionally heated externally and is contained within 1¼ inch stainlesssteel tubing. Goodloe packing is positioned at packing 136 and 137. LABproduct, as well as unreacted benzene and olefin, fall through packing136 into reboiler 142. In reboiler 142, electric heater 140 heats thecontents of reboiler 142 such that heated vapors of benzene and olefinrise from the reboiler 142 to at least reach catalyst zone 132. Asneeded, the bottoms LAB product may be removed from reboiler 142 byopening bottoms valve 144 after passing through line 147 and filter 145.Residual water from the feed mixture, or which otherwise enters thesystem, may be condensed at condenser 121 which is cooled with coolantvia inlet line 122 and exit line 120. The condensed water falls to watertrap 124, which can be drained as needed by opening drain valve 126.Temperature in the system is monitored via thermocouples 138, 130, and165. The system includes pressure release valve 166. A nitrogen blanketover the system is maintained by introduction of nitrogen gas via inletline 154. Level control activator 150 activates bottoms level controlvalve 151 to open when the liquids level in the reboiler rises to thelevel control activator 150.

While the systems depicted in FIG. 1 and FIG. 2 show single catalystzone systems, it must be appreciated that multi-catalyst zone reactorsare within the scope of this invention, as well as multiple ports forinlet feeds, water traps, product removal lines, and so forth. Moreover,the process may be run in batch mode, or in other continuous processesusing plugflow designs, trickle zone designs, and fluidized zonedesigns.

As average molecular weight of olefins increases, particularly when theaverage number of carbons is greater than about 15, the selectivity tothe 2-isomer is less than for lower molecular weight olefins. It is thuspreferred, although not absolutely necessary, that the product of thealkylation using HF is sent to a second, finishing catalyst zone toimprove yield. An example of such a second catalyst is HF-treated claysuch as montmorillonite clay treated in accordance with the invention tohave about 0.5% fluoride and calcined as stated in Huntsman's earlierU.S. Pat. No. 6,630,430 which is fully incorporated herein by reference.

The scheme of FIG. 3 is shown in the context of LAB alkylation based ona feed from a paraffin dehydrogenation facility. Thus, in FIG. 3 freshparaffin is fed to a conventional dehydrogenation apparatus 210 via line211, with recycled paraffin being introduced from the paraffin column250 via line 252. Dehydrogenated paraffin from the dehydrogenationapparatus 210 is then pumped into an alkylation reactor (or reactors)230 that contains hydrogen fluoride. The dehydrogenated paraffin feedmay of course be supplied from any provider. The source ofdehydrogenated paraffin (olefin) is not critical to the practice of thisinvention. LAB product from alkylation unit 230 may thereafter bepurified by a series of distillation towers.

In this regard, alkylation effluent may be delivered to a benzene column240 by way of line 231. It should be appreciated that the alkylationproduct may be sent offsite for purification. Further, the particularpurification scheme used is not critical to the practice of thisinvention. The scheme depicted in FIG. 3 is instead representative of atypical commercial operation. In FIG. 3, unreacted benzene is distilledoff from the crude LAB product. Benzene is then recycled to thealkylation reactor 230. The benzene-free LAB crude product from thebenzene column 240 is pumped through line 241 to paraffin column 250where any paraffin present is distilled off, with the distilled paraffinbeing recycled to paraffin dehydrogenation unit 210 via line 252.Paraffin-free crude LAB from the paraffin column 250 is transported to arefining column 260 where purified LAB is distilled and removed via line262. Heavies (e.g., dialkylates and olefin derivatives) are withdrawnfrom refining column 260 via conduit 261.

It should be appreciated that columns 240, 250, and 260 may bemaintained at conditions (e.g., pressure and temperature) well known tothose of skill in the art and may be packed with conventional materials,if desired.

Hydrocarbon and other base oils such as the vegetable oils are known tobe rarely used in their pure forms in any application, but rathercontain various chemical additives designed to increase the performanceof such oils, or to extend the useful lives of either the oilsthemselves or the equipment in which they are designed to function. Inthis regard, the prior art teaches the use of various oil additiveswhich include without limitation: detergents, dispersants, anti-wearagents, extreme pressure additives, antioxidants, corrosion inhibitors,viscosity modifiers, pour point depressants, antifoam agents, frictionmodifiers, metal deactivators, water scavengers, free radicalscavengers, and compatibilizers.

Although the present invention has been described largely in referenceto the alkylation of benzene using olefins as an alkylating agent, itshould be appreciated that substituted benzenes are also useful asstarting materials within the context of the present invention, providedthat the chemical groups appended to the benzene ring are notprohibitively de-activating of the benzene ring structure. In thisregard, toluene is a functionally equivalent starting material which maybe used in place of all or part of the benzene employed. Othersubstituted benzenes such as xylenes are also useful in this regard, aswell as ethylbenzene, propylbenzene, and butylbenzene.

In cases where a substituted benzene is alkylated in accordance with theprinciples of this invention, the reaction product consistspredominantly of para-substituted reaction products, with some orthosubstitution. Subsequent sulfonation of such a mixture to providesulfonate derivatives results in a mixture of sulfonates or their saltsor esters as well. These materials may be conveniently described by theformula:

in which n is any integer between about 12 and about 30; R₁, R₂, R₃, R₄,and R₅ are each independently selected from the group consisting of:hydrogen, a methyl group, an ethyl group, a propyl group, a butyl group,a sulfonic acid group, an sulfonate group, and salts and esters thereof;B is selected from the group consisting of: hydrogen, methyl, or ethyl;B is attached to any single carbon atom along the —(CH₂)_(n)— portion ofthe alkyl chain; and the total 2-aryl isomer content of said mixture ofalkylbenzenes is between about 8% and about 30% by weight based on thetotal weight of all alkylbenzenes present in said mixture and in whichthe 1-aryl isomer content is less than about 3% by weight based on theweight of all isomers of alkylbenzene derivatives present.

Detergents Useful in Hydrocarbon Oils

One popular class of detergents used in lubricating oils, cuttingfluids, and the like are the oil soluble sulfonates. Within this broadclass are the aromatic sulfonates of the type described in thisspecification, particularly the LAB sulfonates. These materials arepreferred because of their effectiveness and compatibility with othercomponents found in finished oil products, their widespreadavailability, and relatively low cost. Additionally, many of thesedetergent materials are anionic in nature, which means that any one of awide range of selected cationic species may accompany the anionicdetergent, which is of particular benefit when it is desired toincorporate other metals into the composition. The most commonly usedsalts of these acids in hydrocarbon oils are the sodium, potassium,lithium, calcium, magnesium, strontium and barium salts. The “basicsalts” are those metal salts known to the art wherein the metal ispresent in a stoichiometrically larger amount than that necessary toneutralize the acid. The calcium- and barium-overbased petrosulfonicacids are typical examples of such basic salts.

The terms “overbased,” “superbased,” and “hyperbased,” are terms of artwhich are generic to well known classes of the metallic sulfonates andother materials. These overbased materials have also been referred to as“complexes,” “metal complexes,” “high-metal containing salts,” and thelike. Overbased materials are characterized by a metal content in excessof that which would be present according to the stoichiometry of themetal and the particular organic compound reacted with the metal, e.g.,a sulfonic acid. Thus, if a monosulfonic acid such as an LAB sulfonateis neutralized with a basic metal compound, e.g., calcium hydroxide, the“normal” metal salt produced will contain one equivalent of calcium foreach equivalent of acid. However, as is well known in the art, variousprocesses are available which result in an inert organic liquid solutionof a product containing more than the stoichiometric amount of metal.The solutions of these products are referred to herein as overbasedmaterials. Following these procedures, the sulfonic acid or an alkali oralkaline earth metal salt thereof can be reacted with a metal base andthe product will contain an amount of metal in excess of that necessaryto neutralize the acid, for example, 4.5 times as much metal as presentin the normal salt or a metal excess of 3.5 equivalents. The actualstoichiometric excess of metal can vary considerably, for example, fromabout 0.1 equivalent to about 30 or more equivalents depending on thereactions, the process conditions, and the like. These overbasedmaterials useful in preparing the disperse systems will contain fromabout 3.5 to about 30 or more equivalents of metal for each equivalentof material which is overbased. In the present specification and claimsthe term “overbased” is used to designate materials containing astoichiometric excess of metal and is, therefore, inclusive of thosematerials which have been referred to in the art as overbased,superbased, hyperbased, etc., as discussed supra.

The present invention thus provides LAB from which LAB sulfonates may beprepared via conventional sulfonation techniques, and from which mayfurther be prepared overbased sulfonates, using techniques known tothose skilled in the art.

The overbased materials are prepared by treating a reaction mixturecomprising the organic material to be overbased, a reaction mediumconsisting essentially of at least one inert, organic solvent for saidorganic material, a stoichiometric excess of a metal base, and apromoter with an acidic material. The methods for preparing theoverbased materials as well as an extremely diverse group of overbasedmaterials are well known in the prior art and are disclosed for examplein the following U.S. Pat. Nos. 2,616,904; 2,616,905; 2,616,906;2,616,911; 2,616,924; 2,616,925; 2,617,049; 2,695,910, 2,723,234;2,723,235; 2,723,236; 2,760,970; 2,767,164; 2,767,209; 2,777,874;2,798,852; 2,839,470; 2,856,359; 2,859,360; 2,856,361; 2,861,951;2,883,340; 2,915,517; 2,959,551; 2,968,642; 2,971,014; 2,989,463;3,001,981; 3,027,325; 3,070,581; 3,108,960; 3,147,232; 3,133,019;3,146,201; 3,152,991; 3,155,616; 3,170,880; 3,170,881; 3,172,855;3,194,823; 3,223,630; 3,232,883; 3,242,079; 3,242,080; 3,250,710;3,256,186; 3,274,135; 3,492,231; 4,230,586. 6,488,725; 6,197,075;5,944,858; 5,919,276; 4,690,687; 4,505,718; 4,372,862; 4,260,500;4,253,976; 4,252,659; 4,225,446; 4,179,385; 4,164,474; 4,129,508;4,104,180; 6,015,778; and 4,094,801. The foregoing patents discloseprocesses, materials which can be overbased, suitable metal bases,promoters, and acidic materials, as well as a variety of specificoverbased products useful in producing the disperse systems of thisinvention and are, accordingly, incorporated herein by reference.

U.S. Pat. No. 4,086,170 (De Clippeleir et al., Apr. 25, 1978) relates tocalcium sulfonates and concentrated oily solutions thereof that areprepared by reacting a solution of alkylbenzene sulfonic acids with anexcess of a calcium oxide having a medium or low activity towards waterand with carbon dioxide. Oily solutions of overbased calcium sulfonateobtained from such a calcium oxide are limpid and filterable. U.S. Pat.No. 4,604,219 (Whittle, Aug. 5, 1986) is directed to alkaline earthcalcium sulfonates that are derived from natural or synthetic feedstocksor a mixture of both which can be overbased by introducing into amixture comprising a neutral alkaline earth calcium sulfonate, a loweralcohol, a light hydrocarbon diluent carbon dioxide and water. The wateris introduced continuously and at a uniform rate over 1-4 hours,preferably 1-3 hours into the heated mixture with carbon dioxide. Wateris added in a molar ratio water/calcium oxide of 0.1 to 1.2 preferably0.4 to 0.8. It has been found that both the water rate and amount arecritical. It has been unexpectedly found that a superior product isformed by adding water continuously during carbonation rather than allcharged in one or several increments at the beginning of thecarbonation. In this reference, a high calcium sulfonate product withimproved filterability and high clarity is formed with good limeutilization. U.S. Pat. No. 4,775,490 (Nichols et al., Oct. 4, 1988)describes a process for overbasing a substrate comprising mixing thesubstrate, water, a phenol, a source of magnesium and a carbonatingagent, wherein the water is retained throughout the overbasing reactionand provided further that the weight ratio of the water to the magnesiumis in a 10:1 to 1:5 weight ratio, thereby obtaining a magnesiumoverbased substrate. U.S. Pat. No. 4,954,272 (Jao, et al., Sep. 4, 1990)is directed to a process for producing an overbased oil soluble calciumsulfonate having a TBN of 325, said process comprising: (a) diluting aneutral calcium sulfonate with a hydrocarbon solvent and a loweralkanol; (b) adding to the diluted calcium sulfonate solution, CaO,Ca(OH).sub.2 and H₂O in molar ratios of CaO:Ca(OH)₂ of about 90:10 toabout 20:80 and of H₂O:CaO of about 0.15:1 to about 0.30:1; (c) heatingthe sulfonate mixture to a temperature ranging from about 100.degree. F.to about 170.degree. F. under a pressure ranging from about 0 to about50 p.s.i.g.; (d) passing CO₂ into the heated sulfonate mixture for aperiod of about 50 to out 200 minutes; (c) adding a diluent oil to theCO₂ treated sulfonate mixture; (f) separating the solids from the liquidof the sulfonate mixture; and (g) stripping the hydrocarbon solvent fromthe resulting overbased oil soluble sulfonate product having TBN of 325.U.S. Pat. No. 5,259,966 (Burke, Jr., et al., Nov. 9, 1993) provides aprocess for preparing an overbased calcium salt, comprising mixingtogether: (a) an oil-soluble acid material; (b) a promoter comprising:(i) an alcohol or alcohol mixture, and (ii) an inorganic calcium saltother than chloride which is soluble in the alcohol mixture of (i), oran acid or salt which forms said inorganic calcium salt when treatedwith a calcium base; and (c) greater than 1 equivalent of a calcium baseper equivalent of oil-soluble acid material. U.S. Pat. No. 5,534,168(Cleverley et al., Jul. 9, 1996) relates to the use of magnesium oxideof specified, low, reactivity in a process for the production ofoverbased magnesium sulfonates, together with the introduction of waterand an alcohol, into the reaction mixture during carbonation, makes itpossible to prepare high base number products which have very low postcarbonation sediments and which can be purified by rapid filtration.

Other detergents known to those skilled in the art are useful as acomponent of a composition according to the invention in addition to theLAB based detergents described herein.

Dispersants Useful in Hydrocarbon Oils

Although a dispersant used in a hydrocarbon oil may be a multifunctionalmaterial that can confer other beneficial properties to a base oil,dispersants are primarily used in hydrocarbon oils for their ability tomaintain small particles of dirt, combustion products, metal fines, etc.in the liquid phase, to prevent deposition and accumulation of sludgesin places where eddy currents exist in various equipment and wares.

The use of acylated nitrogen compounds as dispersants in lubricants isdisclosed in numerous patents, including U.S. Pat. Nos. 3,172,892;3,219,666; 3,272,746; 3,310,492; 3,341,542; 3,444,170; 3,455,831;3,455,832; 3,576,743; 3,630,904; 3,632,511; 3,804,763; and 4,234,435.

The book “Lubricant Additives” by M. W. Ranney, published by Noyes DataCorporation of Parkridge, N.J. (1973), discloses a number of overbasedmetal salts of various sulfonic acids which are useful asdetergent/dispersant in lubricants. The book also entitled “lubricantAdditives” by C. V. Smallheer and R. K. Smith, published by theLezius-Hiles Co. of Cleveland, Ohio (1967), similarly discloses a numberof overbased sulfonates which are useful as dispersants. U.S. Pat. No.4,100,082 discloses the use of neutral or overbased metal salts oforganic sulfur acids as detergent/dispersants for use in fuels andlubricants.

Ashless detergents and dispersants are so called despite the fact that,depending on its constitution, the dispersant may upon combustion yielda non-volatile material such as boric oxide or phosphorus pentoxide;however, it does not ordinarily contain metal and therefore does notyield a metal-containing ash on combustion. Many types are known in theart, and any of them are suitable for use in the lubricant compositionsand functional fluids of this invention. The following are illustrativeof dispersants, not delimitive of the term, and are incorporated byreference herein:

-   -   (1) Reaction products of carboxylic acids (or derivatives        thereof) containing at least about 34 and preferably at least        about 54 carbon atoms with nitrogen containing compounds such as        amine, organic hydroxy compounds such as phenols and alcohols,        and/or basic inorganic materials. Examples of these “carboxylic        dispersants” are described in many U.S. Pat. Nos., including        3,219,666; 4,234,435; and 4,938,881. These include the products        formed by the reaction of a polyisobutenyl succinic anhydride        with an amine such as a polyethylene amine.    -   (2) Reaction products of relatively high molecular weight        aliphatic or alicyclic halides with amines, preferably        oxyalkylene polyamines. These may be characterized as “amine        dispersants” and examples thereof are described for example, in        the following U.S. Pat. Nos. 3,275,554; 3,438,757; 3,454,555;        and 3,565,804.    -   (3) Reaction products of alkyl phenols in which the alkyl group        contains at least about 30 carbon atoms with aldehydes        (especially formaldehyde) and amines (especially polyalkylene        polyamines), which may be characterized as “Mannich        dispersants.” The materials described in the following U.S. Pat.        Nos. are illustrative: 3,649,229; 3,697,574; 3,725,277;        3,725,480; 3,726,882; and 3,980,569.    -   (4) Products obtained by post-treating the amine or Mannich        dispersants with such reagents as urea, thiourea, carbon        disulfide, aldehydes, ketones, carboxylic acids,        hydrocarbon-substituted succinic anhydrides, nitriles, epoxides,        boron compounds, phosphorus compounds or the like. Exemplary        materials of this kind are described in the following U.S. Pat.        Nos. 3,639,242; 3,649,229; 3,649,659; 3,658,836; 3,697,574;        3,702,757; 3,703,536; 3,704,308; and 3,708,422.    -   (5) Interpolymers of oil-solubilizing monomers such as decyl        methacrylate, vinyl decyl ether and high molecular weight        olefins with monomers containing polar substituents, e.g.,        aminoalkyl acrylates or acrylamides and        poly-(oxyethylene)-substituted acrylates. These may be        characterized as “polymeric dispersants” and examples thereof        are disclosed in the following U.S. Pat. Nos. 3,329,658;        3,449,250; 3,519,565; 3,666,730; 3,687,849; and 3,702,300.

Antiwear Agents

A composition according to this invention may also include a sulfur-,phosphorus-, or sulfur- and phosphorus-containing antiwear agent. Theterm antiwear agent is used to refer to compounds which provide wearprotection properties to lubricating compositions and functional fluids.Antiwear agents are useful in controlling wear and may sometimes alsoact as extreme pressure agents and as antioxidants. These antiwearagents include sulfurized organic compounds, hydrocarbyl phosphates,phosphorus-containing amides, phosphorus-containing carboxylic esters,phosphorus-containing ethers, and dithiocarbamate-containing compounds.Examples of hydrocarbyl phosphates include hydrocarbyl thiophosphates.Thiophosphates may contain from one to about three sulfur atoms,preferably one or two sulfur atoms. Thiophosphates are prepared byreacting one or more phosphites with a sulfurizing agent includingsulfur, sulfur halides, and sulfur containing compounds. Salts ofthiophosphates include zinc dithiophosphates. Other antiwear agentsknown to those skilled in the art are useful as a component of acomposition according to the invention. Other dispersants known to thoseskilled in the art are useful as a component of a composition accordingto the invention.

Anti-Oxidants

A particularly valuable class of additives known as antioxidants arewidely used in lubricating oil formulations, cutting oils, andfunctional fluids. Antioxidants are materials which inhibit oxidativedecomposition of the oil under consideration. Although several examplesare given below, these examples should be considered exemplary only ofthe wide variety of antioxidants which may be usefully combined with thedetergent components of this invention.

In U.S. Pat. No. 2,282,710 to Dietrich issued May 12, 1942 it is knownthat stabilization of petroleum hydrocarbons against the deleteriouscatalytic action of metals may be obtained by compositions containingboth a nitrogen and a sulfur functional group. Various cyclic, aromaticand linear carbon configurations are shown in the sulfur and nitrogencontaining molecules of Dietrich. Dietrich discloses preparing hiscompositions by the use of ethyleneimine. Dietrich further states thathis compounds are particularly effective in retarding the formation ofproducts corrosive to metals, and particularly cadmium, silver, copper,lead and like bearing alloys under normal service conditions.

German OLS 1,066,019 published Sep. 24, 1959 by Holtschmitt et aldescribes various condensation products of thioglycol and nitrogencontaining materials. Holtschmitt shows his compounds as containing freehydroxyl groups. Holtschmitt further discloses the use of aromaticamines containing a short aliphatic group on the aromatic ring, e.g.toluidine.

It is known from an article entitled: “Thioglycol Polymers IHydrochloric Acid-Catalysed Auto Condensation of Thiodiglycol” byWoodward, Journal of Polymer Science the OL XLI, Pages 219-223 (1959),that the properties of a sulfur and oxygen containing compound allowend-to-end condensation. It is further known from the Woodward articlethat multiple sulfur linkages within the molecule, e.g. disulfides,trisulfides, and the like may be obtained.

It is further known that various amines may be utilized in antioxidantcompositions. Phenothiazine compounds are known in lubricant productsfrom U.S. Pat. No. 2,781,318 issued Feb. 12, 1957 to Cyphers. The alkylphenothiazines of Cyphers are alkylated on the phenylene rings of thephenothiazine structure. Cyphers does not show or suggest the alkylationof the amine nitrogen in phenothiazine. The Cyphers patent is directedto the utility of phenothiazine as an antioxidant and corrosioninhibiting additive for ester, polyester, polyether and other syntheticlubricants.

U.S. Pat. No. 3,536,706 issued Oct. 27, 1970 to Randell suggests thatphenothiazines may be used as additives for synthetic lubricants. Thephenothiazines particularly described by Randell are those containingtertiary alkyl substituents having from 4 to 12 carbon atoms on the arylgroups which make up the phenothiazine structure. Randell also disclosesfused rings on the two phenylene groups which make up the phenothiazinestructure. Stated otherwise, Randell allows the utilization ofnaphthalene for at least one of the two aryl groups in the phenothiazinestructure. U.S. Pat. No. 3,803,140 issued to Cook et al on Apr. 9, 1974describes various tertiary alkyl derivatives of phenothiazine. N-alkylsubstitution or N-alkenyl substitution is described on the phenothiazinestructure. Ring alkylation when the phenothiazine is in the freenitrogen form is also shown. Cook et al express a preference for non-Nsubstituted phenothiazine derivatives.

Cook et al also suggest that organic materials which are susceptible tooxidative degradation may benefit through the use of the compounds oftheir invention. Such uses include antioxidants for aliphatichydrocarbons such as gasoline, lubricating oils, lubricating greases,mineral oils, waxes, natural and synthetic polymers such as rubber,vinyl, vinylidene, ethers, esters, amides and urethanes. The compoundsof Cook et al are also suggested for stabilizing aldehydes andunsaturated fatty acids or esters thereof. Still further utilitiessuggested by Cook et al include the stabilization of organo-metalloidsubstances such as silicone polymers. Another class of uses of thecompounds of Cook et al include the stabilization of vitamins, essentialoils, ketones and ethers.

Normant in U.S. Pat. No. 3,560,531 issued Feb. 2, 1971, describesmetallation of materials having active hydrogens includingphenothiazine. U.S. Pat. No. 3,344,068 issued Sep. 26, 1967, to Waightet al describes antioxidants for ester-based lubricants. Waight et al'scompounds have an N-hydrocarbyl substituted phenothiazine structure. TheN-substituted phenothiazine compounds of Waight et al are alsosubstituted in at least one position on the fused aromatic nuclei. Asecond required component in the compositions of Waight et al is asecondary aromatic amine having two aromatic groups attached to thenitrogen atom.

The preparation of alkylthioalkanols which are useful as intermediatesfor preparing the compounds of the present invention are described inU.S. Pat. No. 4,031,023 to Musser et al.

U.S. Pat. No. 2,194,527 to Winthrop et al which issued Nov. 24, 1959,describes pharmaceutical compounds such asomega-(10-phenothiazinyl)alkyl di-alkyl sulfonium salts which are usefulas spasmolytics and in particular antihistaminics. U.S. Pat. No.3,376,224 issued Apr. 2, 1968 to Elliott et al describes phenothiazinederivatives which are stated to be N-substituted methylene compoundswhich contain an ether linkage between the methylene group and an alkylor cycloalkyl radical. According to Elliott et al, the alkyl orcycloalkyl radical may carry an alkoxy or other non-reactivesubstituent.

U.S. Pat. No. 4,915,858 describes a composition of matter which is theamine terminated reaction product obtained from two equivalents of asecondary aromatic monoamine with at least two equivalents of abetathiodialkanol. Other antioxidants known to those skilled in the artare useful as a component of a composition according to the invention.

Corrosion Inhibitors

Corrosion-inhibiting agents are exemplified by chlorinated aliphatichydrocarbons such as chlorinated wax; organic sulfides and polysulfidessuch as benzyl disulfide, bis(chlorobenzyl) disulfide, dibutyltetrasulfide, sulfurized methyl ester of oleic acid, sulfurizedalkylphenol, sulfurized dipentene, and sulfurized terpene;phosphosulfurized hydrocarbons such as the reaction product of aphosphorus sulfide with turpentine or methyl oleate; phosphorus estersincluding principally dihydrocarbon and trihydrocarbon phosphites suchas dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite, dipentyl phenyl phosphite, tridecyl phosphite,distearyl phosphite, dimethyl naphthyl phosphite, oleyl 4-pentylphenylphosphite, polypropylene (molecular weight 500)-substituted phenylphosphite, diisobutyl-substituted phenyl phosphite; metalthiocarbamates, such as zinc dioctyldithiocarbamate, and bariumheptylphenyl dithiocarbamate; Group II metal phosphorodithioates such aszinc dioctylphosphorodithioate, zinc dicyclohexylphosphorodithioate,barium di(heptylphenyl)phosphorodithioate, cadmiumdinonylphosphorodithioate, and the zinc salt of a phosphorodithioic acidproduced by the reaction of phosphorus pentasulfide with an equimolarmixture of isopropyl alcohol and n-hexyl alcohol. Other corrosioninhibitors known to those skilled in the art are useful as a componentof a composition according to the invention.

Viscosity Modifiers

Viscosity modifiers generally are polymeric materials characterized asbeing hydrocarbon-based polymers generally having number averagemolecular weights between about 25,000 and 500,000 more often betweenabout 50,000 and 200,000. Such materials are typically added to ahydrocarbon based oil and the oil is heated, with agitation, until thepolymeric material is dissolved.

Polyisobutylene has been used as a viscosity modifier in lubricatingoils. Polymethacrylates (PMA) are prepared from mixtures of methacrylatemonomers having different alkyl groups. Most PMA's areviscosity-modifiers as well as pour point depressants. The alkyl groupsmay be either straight chain or branched chain groups containing from 1to about 18 carbon atoms.

Ethylene-propylene copolymers, generally referred to as OCP can beprepared by copolymerizing ethylene and propylene, generally in asolvent, using known catalysts such as a Ziegler-Natta initiator. Theratio of ethylene to propylene in the polymer influences theoil-solubility, oil-thickening ability, low temperature viscosity, pourpoint depressant capability and engine performance of the product. Thecommon range of ethylene content is 45-60% by weight and typically isfrom 50% to about 55% by weight. Some commercial OCP's are terpolymersof ethylene, propylene and a small amount of nonconjugated diene such as1,4-hexadiene. In the rubber industry, such terpolymers are referred toas EPDM (ethylene propylene diene monomer). The use of OCP's asviscosity modifiers in lubricating oils has increased rapidly sinceabout 1970, and the OCP's are currently one of the most widely usedviscosity modifiers for motor oils.

Esters obtained by copolymerizing styrene and maleic anhydride in thepresence of a free radical initiator and thereafter esterifying thecopolymer with a mixture of C₄₋₁₈ alcohols also are useful as viscositymodifying additives in motor oils. The styrene esters generally areconsidered to be multifunctional premium viscosity modifiers. Thestyrene esters in addition to their viscosity modifying properties alsoare pour point depressants and exhibit dispersancy properties when theesterification is terminated before its completion leaving someunreacted anhydride or carboxylic acid groups. These acid groups canthen be converted to imides by reaction with a primary amine.

Hydrogenated styrene-conjugated diene copolymers are another class ofcommercially available viscosity modifiers for motor oils. Examples ofstyrenes include styrene, alpha-methyl styrene, ortho-methyl styrene,meta-methyl styrene, para-methyl styrene, para-tertiary butyl styrene,etc. Preferably the conjugated diene contains from four to six carbonatoms. Examples of conjugated dienes include piperylene,2,3-dimethyl-1,3-butadiene, chloroprene, isoprene and 1,3-butadiene,with isoprene and butadiene being particularly preferred. Mixtures ofsuch conjugated dienes are useful.

The styrene content of these copolymers is in the range of about 20% toabout 70% by weight, preferably about 40% to about 60% by weight. Thealiphatic conjugated diene content of these copolymers is in the rangeof about 30% to about 80% by weight, preferably about 40% to about 60%by weight.

These copolymers typically have number average molecular weights in therange of about 30,000 to about 500,000, preferably about 50,000 to about200,000. The weight average molecular weight for these copolymers isgenerally in the range of about 50,000 to about 500,000, preferablyabout 50,000 to about 300,000.

The above described hydrogenated copolymers have been described in theprior art such as in U.S. Pat. Nos. 3,551,336; 3,598,738; 3,554,911;3,607,749; 3,687,849; and 4,181,618 which are hereby incorporated byreference for their disclosures of polymers and copolymers useful asviscosity modifiers in oil compositions according to this invention. Forexample, U.S. Pat. No. 3,554,911 describes a hydrogenated randombutadiene-styrene copolymer, its preparation and hydrogenation. Thedisclosure of this patent is incorporated herein by reference.Hydrogenated styrene-butadiene copolymers useful as viscosity modifiersin the lubricating oil compositions of the present invention areavailable commercially from, for example, BASF under the general tradedesignation “Glissoviscal”. A particular example is a hydrogenatedstyrene-butadiene copolymer available under the designation Glissoviscal5260 which has a molecular weight, determined by gel permeationchromatography, of about 120,000. Hydrogenated styrene-isoprenecopolymers useful as viscosity modifiers are available from, forexample, The Shell Chemical Company under the general trade designation“Shellvis”. Shellvis 40 from Shell Chemical Company is identified as adiblock copolymer of styrene and isoprene having a number averagemolecular weight of about 155,000, a styrene content of about 19 molepercent and an isoprene content of about 81 mole percent. Shellvis 50 isavailable from Shell Chemical Company and is identified as a diblockcopolymer of styrene and isoprene having a number average molecularweight of about 100,000, a styrene content of about 28 mole percent andan isoprene content of about 72 mole percent. Other viscosity modifiersknown to those skilled in the art are useful as a component of acomposition according to the invention.

Pour Point Depressants

Pour point depressants may also be included in a formulation accordingto the invention. They are a particularly useful type of additive oftenincluded in the lubricating oils and functional fluids such as cuttingoils or other lubricants, and often comprise oil-soluble polymers.Examples of pour point depressants include those on page 8 of LubricantAdditives” by C. V. Smalheer and R. Kennedy Smith (Lesius-Hiles CompanyPublishers, Cleveland, Ohio, 1967, which book is incorporated in itsentirety herein by reference thereto). Other pour point depressantsknown to those skilled in the art are useful as a component of acomposition according to the invention.

Antifoam Agents

Anti-foam agents may be used to reduce or prevent the formation ofstable foam and include silicones or organic polymers. Examples of theseand additional anti-foam compositions are described in “Foam ControlAgents”, by Henry T. Kerner (Noyes Data Corporation, 1976), pages125-162, which book is incorporated in its entirety herein by referencethereto. Other antifoam agents known to those skilled in the art areuseful as a component of a composition according to the invention.

Friction Modifiers

The oil compositions of the present invention also may contain at leastone friction modifier to provide the lubricating oil with the properfrictional characteristics for a given application. Various amines,particularly tertiary amines are effective friction modifiers. Examplesof tertiary amine friction modifiers include N-fatty alkyl-N,N-diethanolamines, N-fatty alkyl-N,N-diethoxy ethanol amines, etc. Such tertiaryamines can be prepared by reacting a fatty alkyl amine with anappropriate number of moles of ethylene oxide. Tertiary amines derivedfrom naturally occurring substances such as coconut oil and oleoamineare available from Armour Chemical Company under the trade designation“Ethomeen”. Particular examples are the Ethomeen-C and the Ethomeen-Oseries. Sulfur-containing compounds such as sulfurized C₁₂₋₂₄ fats,alkyl sulfides and polysulfides wherein the alkyl groups contain from 1to 8 carbon atoms, and sulfurized polyolefins also may function asfriction modifiers in the lubricating oil compositions of the invention.Other function modifiers known to those skilled in the art are useful asa component of a composition according to the invention.

Base Oils

The present invention is broad with respect to the selection of base oilcomponent used in its blending. Typically, compositions according to theinvention comprise a base oil as a major component of the composition.For purposes of this specification and the appended claims the term“base oil” as used herein is intended to include those materials whichare recognized as possessing lubricity characteristics by those ofordinary skill in the art. Such materials include, without limitation,materials falling within the following classes: 1) lubricity agents suchas synthetic polymers (e.g., polyisobutene having a number averagemolecular weight in the range of about 750 to about 15,000, as measuredby vapor phase osmometry or gel permeation chromatography); 2) thepolyol ethers (e.g., poly(oxyethylene-oxypropylene)ethers); 3) esteroils including natural and synthetic triglycerides; 4) natural oilfractions such as mineral oils and those referred to as bright stocks(including all relatively viscous products formed during conventionallubricating oil manufacture from petroleum). Thus, any oil or othermaterial recognized by those skilled in the art as possessing lubricitycharacteristics may be used as a base oil for purposes of thisinvention.

Ashless Dispersants

Within the prior art in the realm of motor fuel are a wide range ofmaterials regarded as ashless dispersants by those of ordinary skill insuch art. There are a great many materials capable of functioning inthis regard, including various Mannich bases, ethyleneamines,polyalkylene polyamines, and other primary, secondary and tertiaryamines known in the art. The following is provided to be exemplary andnot delimitive of the scope of ashless dispersants which may be employedin the context of the present invention.

A large number of such ashless dispersants are derivatives of highmolecular weight carboxylic acid acylating agents. Typically, theacylating agents are prepared by reacting an olefin (e.g., a polyalkenesuch as polybutene) or a derivative thereof, containing for example atleast about 10 aliphatic carbon atoms or generally at least 30 to 50aliphatic carbon atoms, with an unsaturated carboxylic acid orderivative thereof such as acrylic acid, methylacrylate, maleic acid,fumaric acid and maleic anhydride. Dispersants are prepared from thehigh molecular weight carboxylic acid acylating agents by reaction with,for example, amines characterized by the presence within their structureof at least one N—H group, alcohols, reactive metal or reactive metalcompounds, and combinations of the above. The prior art relative to thepreparation of such carboxylic acid derivatives is summarized in U.S.Pat. No. 4,234,435.

It also has been suggested that the carboxylic acid derivativecompositions such as those described above can be post-treated withvarious reagents to modify and improve the properties of thecompositions. Acylated nitrogen compositions prepared by reacting theacylating reagents described above with an amine can be post-treated,for example, by contacting the acylated nitrogen compositions thusformed with one or more post-treating reagents selected from the groupconsisting of boron oxide, boron oxide hydrate, boron halides, boronacids, esters of boron acid, carbon disulfide, sulfur, sulfur chlorides,alkenyl cyanides, carboxylic acid acylating agents, aldehydes, ketones,phosphoric acid, epoxides, etc. Lists of the prior art relating topost-treatment of carboxylic ester and amine dispersants with reagentssuch as those described above are contained in a variety of patents suchas U.S. Pat. No. 4,203,855 (Col. 19, lines 16-34) and U.S. Pat. No.4,234,435 (Col. 42, lines 33-46). The use of isophthalic andterephthalic acids as corrosion-inhibitors is described in U.S. Pat. No.2,809,160. The corrosion-inhibitors are used in combination withdetergent additives.

The preparation of lubricating oils containing ashless dispersantsobtained by reaction of aliphatic and aromatic polycarboxylic acids withacylated amines have been described previously. For example, U.S. Pat.No. 4,234,435 describes lubricating oils containing carboxylic acidderivative compositions prepared by post-treating acylated amines with avariety of compositions including carboxylic acid acylating agents suchas terephthalic acid and maleic acid. U.S. Pat. No. 3,287,271 and FrenchPat. No. 1,367,939 describe detergent-corrosion inhibitors forlubricating oils prepared by combining a polyamine with a high molecularweight succinic anhydride and thereafter contacting the resultingproduct with an aromatic dicarboxylic acid of from 8 to 14 carbon atomswherein the carboxyl groups are bonded to annular carbon atoms separatedby at least one annular carbon atom. Illustrative of such aromaticdicarboxylic acids are isophthalic acid, terephthalic acid and variousderivatives thereof. Lubricating compositions containing amine salts ofa phthalic acid are described in U.S. Pat. No. 2,900,339. The aminesalts are thermally unstable salts of the phthalic acid and a basictertiary amine. U.S. Pat. No. 3,692,681 describes dispersions ofphthalic acid in hydrocarbon media containing highly hindered acylatedalkylene polyamines. The polyamines are prepared by reaction of analkenyl succinic anhydride with an alkylene polyamine such as ethylenepolyamine or propylene polyamine. The terephthalic acid or itsderivative is dissolved in an auxiliary solvent such as a tertiaryalcohol or DMSO, and a terephthalic acid solution is combined with ahydrocarbon solution containing the hindered acylated amine addressdetergent. The auxiliary solvent then is removed.

U.S. Pat. No. 3,216,936 describes lubricant additives which arecompositions derived from the acylation of alkylene polyamines. Morespecifically, the compositions are obtained by reaction of an alkyleneamine with an acidic mixture consisting of a hydrocarbon-substitutedsuccinic acid having at least about 50 aliphatic carbon atoms in thehydrocarbon group and an aliphatic monocarboxylic acid, and thereafterremoving the water formed by the reaction. The ratio of equivalents ofsaid succinic acid to the mono-carboxylic acid in the acidic mixture isfrom about 1:0.1 to about 1:1. The aliphatic mono-carboxylic acidscontemplated for use include saturated and unsaturated acids such asacetic acid, dodecanoic acid, oleic acid, naphthenic acid, formic acid,etc. Acids having 12 or more aliphatic carbon atoms, particularlystearic acid and oleic acid, are especially useful. The productsdescribed in the '936 patent also are useful in oil-fuel mixtures fortwo-cycle internal combustion engines.

British Pat. No. 1,162,436 describes ashless dispersants useful inlubricating compositions and fuels. The compositions are prepared byreacting certain specified alkenyl substituted succinimides or succinicamides with a hydrocarbon-substituted succinic acid or anhydride. Thearithmatic mean of the chain lengths of the two hydrocarbon substituentsis greater than 50 carbon atoms. Formamides of monoalkenyl succinimidesare described in U.S. Pat. No. 3,185,704. The formamides are reported tobe useful as additives in lubricating oils and fuels.

U.S. Pat. Nos. 3,639,242 and 3,708,522 describe compositions prepared bypost-treating mono- and polycarboxylic acid esters with mono- orpolycarboxylic acid acylating agents. The compositions thus obtained arereported to be useful as dispersants in lubricants and fuels.

One preferred method for preparing compositions according to theinvention is to begin with a major amount of a base oil material and addthe other selected ingredients to the base oil, with sufficientagitation to provide a homogeneous mixture within a reasonable time.When the viscosity of the additive is much greater than that of the baseoil, it is beneficial to provide heating to the base oil to facilitatedissolution and homogeneity. This is especially true in the cases wherepolymeric materials are added to base oils. However, the dissolution ofall of the additives used in the invention in a base oil is well knownin the art and is thus within the skill level of an ordinary artisan inthe oil additives field.

The compositions of the present invention may vary widely in compositiondepending upon the intended use of the final composition. However, thoseof ordinary skill in formulating lubricating oils, functional fluids,cutting oils, emulsions, etc., in which LAB based detergent materialsare used as a component readily recognize that the detergents preparedfrom LAB materials provided by the invention may be used as direct,drop-in substitutes for many detergent components in currentformulations, including those which are based on linear alkylbenzenesand those which are not. Compositions which include detergents basedupon the linear alkylbenzenes of the invention offer superior detergencyover formulations which contain linear alkylbenzene based detergentmaterials of the prior art, on a molar basis, owing to the unique isomerdistribution provided by the present invention.

Another aspect of the present invention is the use of the LABsurfactants in fuel formulations on which various internal combustionengines including diesel, automobile, and jet engines may be operated.Since the LAB surfactants of this invention may be anionic in nature,such as in the cases when the detergent molecule is a sulfonate, it ispossible to provide charge balance using a cation which is known toimpart beneficial properties to motor fuels. Such cations may includethe alkali and alkaline earth metals as the use of such are well knownfor the properties they impart to fuel compositions. Further, the priorart discloses many ashless dispersants useful as additives in fuels andlubricant compositions. Many of these are cationic in nature and arethus capable of providing charge balance to chemical compounds in whichthe anionic portion is derived from the LAB according to this invention,to provide a neutral, oil or fuel soluble material which possesses bothdetergent and dispersant characteristics.

One particular and surprising advantage of using the catalysts of thisinvention to produce alkylbenzenes is that a low content ofdialkylbenzene components are found in the alkylbenzene product mixture.This is important since dialkylbenzenes are generally regarded asundesirable, and the presence of such species tends to raise theviscosity of the alkylbenzene reaction product mixture. Thus, usingconventional alkylation technology known in the art, it is common foralkylbenzenes produced in accordance with prior art methods to have aviscosity greater than about 145 SUS viscosity units at a temperature of37.8 degrees centigrade. However, alkylation of benzene with olefins inthe C₁₆-C₃₀ range in accordance with this invention provides a producthaving an SUS viscosity of 85 at 37.8 degrees centigrade. Generallyspeaking, alkylbenzenes made by alkylation of benzene with olefins inthe C₁₆-C₃₀ range using catalysts an procedures taught herein results inthe alkylbenzenes containing less than 1% of dialkylbenzenes.

A material sold by Huntsman LLC of Houston Tex. is sold under the tradename “Alkylate 300” and is available from Huntsman in commercialquantities. Huntsman's Alkylate 300 is has a 2-phenyl isomer content inthe range of between about 10 and 13% by weight of all alkylbenzeneisomers present, and is substantially free of benzene inasmuch as we areunable to detect any benzene present down to a level of 100 parts perbillion.

Huntsman's Alkylate 300 is suitable for sulfonation from whichalkylbenzene sulfonates may be produced using means known to thoseskilled in the art which may comprises reacting the Alkylate 300 withsulfuric acid and/or SO₃ at elevated temperatures. A sulfonation methodinvolving an air/sulfur trioxide mixture which is applicable toproviding sulfonated Alkylate 300 is described in U.S. Pat. No.3,427,342 to Brooks et al., entitled “Continuous Sulfonation Process,”which is incorporated by reference herein. In an embodiment, a sulfurtrioxide to alkyl aromatic product molar ratio used for sulfonation is1.03.

The sulfonated Alkylate 300 emerges from the sulfonation reactor as theacid form of the sulfonate, which is sometimes referred to as analkylbenzenesulfonic acid. This acid may be neutralized usingconventional alkalis such as hydroxides, oxides, carbonates, etc. ofalkali metals, alkaline earth metals, and combinations thereof. Onepopular method for using Alkylate 300 is to sulfonate the Alkylate 300to form the alkylbenzenesulfonic acid, and to subsequently neutralizethe sulfonic acid so obtained with a calcium or magnesium salt, andsubsequently overbasing by successive additions of carbon dioxide andmagnesium and/or calcium ion until a material having a desired basenumber is obtained. The resulting material is an oil-soluble overbasedsulfonate, which is suitable for use as a detergent additive forlubricants and oils.

Thus, a composition of one form of the present invention is a mixture oftwo or more alkylbenzenes which have a 2-aryl isomer content in therange of between about 8 and 30% by weight based on the total weight ofall of the linear monoalkylbenzenes (including 2-aryl and non-2-aryl)present in the mixture. In general, alkylbenzenes anddetergent-dispersant products derived therefrom according to thisinvention are substantially free from benzene, having a benzene contentless than 2 ppm in one form of the invention, less than 1 ppm in anotherform of the invention, less than 0.5 ppm in another form of theinvention and less than 100 parts per billion in another form of theinvention. In general, an alkylbenzene and detergent-dispersant productsderived therefrom according to the invention contain less than about 28%branching. Further, the alkylbenzenes according to the invention aresubstantially free from 1-aryl isomers of alkylbenzenes, which areisomers where the benzene ring is attached to the 1-position of a linearalkyl chain having more than about 14 carbon atoms.

Consideration must be given to the fact that although this invention hasbeen described and disclosed in relation to certain preferredembodiments, obvious equivalent modifications and alterations thereofwill become apparent to one of ordinary skill in this art upon readingand understanding this specification and the claims appended hereto. Thepresent disclosure includes the subject matter defined by anycombination of any one of the various claims appended hereto with anyone or more of the remaining claims, including the incorporation of thefeatures and/or limitations of any dependent claim, singly or incombination with features and/or limitations of any one or more of theother dependent claims, with features and/or limitations of any one ormore of the independent claims, with the remaining dependent claims intheir original text being read and applied to any independent claim somodified. This also includes combination of the features and/orlimitations of one or more of the independent claims with the featuresand/or limitations of another independent claim to arrive at a modifiedindependent claim, with the remaining dependent claims in their originaltext being read and applied to any independent claim so modified.

The present invention includes any overbased sulfonate described hereinwith any one or more conventional additives useful in motor oils and thelike specified herein.

In addition, the 2-aryl isomer content has been described in quantitiesrelative to the total weight of a mixture in which such isomers arepresent. The present invention also includes embodiments in which thepercentages specified herein relate to the 2-isomer content whencalculated by taking the weight of the 2-isomer content in a givensample, and dividing it by the weight in the same sample of linearalkylbenzenes, and multiplying this quotient by 100 to arrive at apercentage 2-isomers, with all remaining claim limitations heldconstant. A specification sheet for Alkylate 300 is available fromHuntsman LLC of Houston, Tex.

Thus, the presently disclosed invention is intended to cover all suchmodifications and alterations, and is limited only by the scope of theclaims which follow, in view of the foregoing and other contents of thisspecification.

1) A mixture of alkylbenzenes from which an overbased alkaline earthsulfonate may be prepared, which mixture comprises two or more 2-arylisomers of alkylbenzenes having the structure:

in which: n is any integer between 12 and 30; R₁, R₂, R₃, R₄, and R₅ areeach independently selected from the group consisting of: hydrogen, amethyl group, an ethyl group, a propyl group, and a butyl group; B isselected from the group consisting of: hydrogen, methyl, or ethyl; B isattached to any single carbon atom along the —(CH₂)_(n)— portion of thealkyl chain; and the total 2-aryl isomer content of said mixture ofalkylbenzenes is between about 8% and about 30% by weight based on thetotal weight of all alkylbenzenes present in said mixture. 2) A mixtureaccording to claim 1 which contains less than about 2 parts per millionof benzene by weight based on the total weight of said mixture. 3) Amixture according to claim 1 which contains less than about 1 parts permillion of benzene by weight based on the total weight of said mixture.4) A mixture according to claim 1 which contains less than about 0.5parts per million of benzene by weight based on the total weight of saidmixture. 5) A mixture according to claim 1 which contains less thanabout 100 parts per billion of benzene by weight based on the totalweight of said mixture. 6) A mixture according to claim 1 in which B ishydrogen for between about 72% and about 98% of all alkylbenzenespresent, by weight, based on the total weight of said mixture. 7) Amixture according to claim 1 in which the amount of 1-aryl isomerspresent is less than about 0.3% by weight based on the total weight ofsaid mixture. 8) A mixture according to claim 1 in which the amount of1-aryl isomers present is any amount in the range of between about 0.01%to about 0.3% by weight based on the total weight of said mixture. 9) Anoverbased sulfonate made by sulfonating a mixture according to claim 1,and subsequently overbasing with an alkaline earth metal and carbondioxide, or an alkali metal and carbon dioxide, until the base number ofsaid overbased sulfonate is at least
 250. 10) A process for producing anoverbased sulfonate which comprises the steps of: a) providing a mixtureof aromatic alkylates which comprises two or more 2-aryl isomers havingthe structure:

in which: n may be equal to any integer between 12 and 30; R₁, R₂, R₃,R₄, and R₅ are each independently selected from the group consisting of:hydrogen, a methyl group, an ethyl group, a propyl group, and a butylgroup; B is selected from the group consisting of: hydrogen, methyl, orethyl; B is attached to any single carbon atom along the —(CH₂)_(n)—portion of the alkyl chain; and the 2-aryl content of said mixture ofaromatic alkylates is between about 8% and about 30% by weight based onthe total weight of said mixture; said mixture contains an amount of1-aryl isomer that is less than about 3% by weight based on the totalweight of all aromatic alkylates present in said mixture; and b)reacting said mixture of aromatic alkylates with a source of sulfurtrioxide, thus yielding an alkylaryl sulfonic acid; c) combining saidalkylaryl sulfonic acid with: i) a source of an alkaline earth metalselected from calcium, strontium, and magnesium; ii) water; iii) a loweralcohol; iv) optionally, a hydrocarbon solvent; and v) carbon dioxide,under conditions favorable to formation of an overbased sulfonate,wherein the final overbased sulfonate has a total base number of anyvalue in the range of about 200 to about
 375. 11) A process according toclaim 10 further comprising the step of: d) filtering said overbasedsulfonate to remove solids. 12) A process according to claim 11 furthercomprising the step of: e) diluting said overbased solvent with amaterial selected from the group consisting of: a hydrocarbon solventand a base oil. 13) A process according to claim 10 in which saidmixture of aromatic alkylates contains less than about 2 ppm benzene.14) A process according to claim 10 in which said mixture of aromaticalkylates contains less than about 1 ppm benzene. 15) A processaccording to claim 10 in which said mixture of aromatic alkylatescontains less than about 0.5 ppm benzene. 16) A process according toclaim 10 in which said mixture of aromatic alkylates contains less thanabout 0.3% by weight of 1-aryl isomers of alkylbenzenes. 17) Acomposition useful as a lubricant, which composition is formed by mixinga base oil with an effective detergent-dispersant amount of analkylbenzene-derived detergent component that is made by sulfonating,and optionally overbasing, a mixture of alkylbenzenes, which mixturecomprises two or more 2-aryl isomers of alkylbenzenes having thestructure:

in which: n is any integer between 12 and 30; R₁, R₂, R₃, R₄, and R₅ areeach independently selected from the group consisting of: hydrogen, amethyl group, an ethyl group, a propyl group, and a butyl group; B isselected from the group consisting of: hydrogen, methyl, or ethyl; B isattached to any single carbon atom along the —(CH₂)_(n)— portion of thealkyl chain; and the total 2-aryl isomer content of said mixture ofalkylbenzenes is between about 8% and about 30% by weight based on thetotal weight of all alkylbenzenes present in said mixture. 18) Acomposition according to claim 17 wherein said mixture of alkylbenzenescontain any amount between about 10% and about 20% of said 2-arylisomers, by weight, based on the total weight of all alkylbenzenespresent in said mixture. 19) A composition according to claim 17 inwhich said mixture of alkylbenzenes contain less than about 2 ppm ofbenzene by weight. 20) A composition according to claim 17 in which saidmixture of alkylbenzenes contain less than about 1 ppm of benzene byweight. 21) A composition according to claim 17 in which said mixture ofalkylbenzenes contain less than about 0.5 ppm of benzene by weight. 22)A composition according to claim 17 wherein said alkylbenzene-deriveddetergent component is present in any amount between 0.03% and 49.95% byweight based upon the total weight of said composition useful as alubricant. 23) A composition as in claim 17 wherein thealkylbenzene-derived detergent component is predominantly comprised ofmolecules which comprise only one alkyl group bonded to a benzene ring,and wherein none of R₁, R₂, R₃, R₄, or R₅ are hydrocarbyl. 24) Acomposition as in claim 23 wherein the alkyl group is substantiallylinear. 25) A composition as in claim 23 wherein the alkyl group is abranched alkyl group. 26) A composition according to claim 17 whereinsaid alkylbenzene-derived detergent component is present in any amountbetween 0.10% and 25.00% by weight based upon the total weight of saidcomposition useful as a lubricant. 27) A composition according to claim17 in which said mixture of alkylbenzenes contains less than about 0.3%by weight 1-aryl isomers of alkylbenzenes. 28) A composition accordingto claim 17 in which the 1-aryl alkylbenzenes isomers content of saidmixture of alkylbenzenes is any value in the range of between about0.01% and about 0.3% by weight based on the total weight of saidmixture. 29) A composition useful as a lubricant that is formed fromcomponents comprising: a) an alkylbenzene-derived component present inany amount between about 0.01% and about 50% by weight based upon thetotal weight of the composition, which alkylbenzene-derived component isselected from the group consisting of: sulfonates and overbasedsulfonates of an alkylbenzenes mixture in which the content of 2-arylisomers in said alkylbenzenes mixture is any value between about 10% andabout 30% by weight based on the total weight of the alkylbenzenesmixture, wherein said 2-aryl isomers are described by the generalformula:

in which n is equal to any integer between about 14 and about 27, and inwhich one and only one of R₁, R₂, R₃, R₄, and R₅ is a sulfur-containingappendage selected from the group consisting of: a sulfonic acid group,a sulfonate group, and a sulfonate ester group; and wherein the groupsR₁, R₂, R₃, R₄, and R₅ which are not a sulfur-containing group are eachindependently selected from the group consisting of: hydrogen, a methylgroup, an ethyl group, a propyl group, and a butyl group; and b) atleast 50% by weight of a base oil, wherein said alkylbenzene-derivedcomponent contains one or more metals selected from the group consistingof: lithium, sodium, potassium, strontium, magnesium, and calcium. 30) Acomposition according to claim 29 in which said alkylbenzene-derivedcomponent is a mixture of sulfonate salts of metals selected from thegroup consisting of: alkali metals or alkaline earth metals. 31) Acomposition according to claim 29 in which said alkylbenzene-derivedcomponent is an overbased sulfonate which comprises a mixture of isomersof alkaline earth metal alkylbenzene sulfonates, which mixture includesone or more metals selected from the group consisting of: Sr, Mg, Ba,and Ca. 32) A composition according to claim 29 in which saidalkylbenzene mixture contains less than about 2 parts per million ofbenzene by weight based on the total weight of said alkylbenzenemixture. 33) A composition according to claim 29 in which saidalkylbenzene mixture contains less than about 1 parts per million ofbenzene by weight based on the total weight of said alkylbenzenemixture. 34) A composition according to claim 29 in which saidalkylbenzene mixture contains less than about 0.5 parts per million ofbenzene by weight based on the total weight of said alkylbenzenemixture. 35) A composition according to claim 29 in which saidalkylbenzene mixture contains less than about 100 parts per billion ofbenzene by weight based on the total weight of said alkylbenzenesmixture. 36) A composition according to claim 29 in which B is hydrogenfor between about 72% and about 98% of all alkylbenzenes present in saidalkylbenzene mixture, by weight, based on the total weight of saidalkylbenzenes mixture. 37) A composition according to claim 29 in whichthe amount of 1-aryl isomers present in said alkylbenzene mixture isless than about 0.3% by weight based on the total weight of saidalkylbenzenes mixture. 38) A composition according to claim 29 in whichthe amount of 1-aryl isomers present in said alkylbenzene mixture is anyamount in the range of between about 0.01% to about 0.3% by weight basedon the total weight of said alkylbenzenes mixture. 39) A composition ofmatter comprising: a) a major amount of a material selected from thegroup consisting of: a motor fuel, a hydrocarbon diluent, or a base oil;and b) a minor amount of a mixture of alkaline earth metal salts ofoverbased alkylbenzene sulfonates, which mixture comprises two or more2-aryl isomers of overbased alkylbenzene sulfonates which are derivedfrom a mixture of alkylbenzene sulfonates comprising at least two 2-arylisomers of the structure:

in which: n is any integer between about 12 and about 30; R₁, R₂, R₃,R₄, and R₅ are each independently selected from the group consisting of:hydrogen, a methyl group, an ethyl group, a propyl group, a butyl group,a sulfonic acid group, and a sulfonate group; B is selected from thegroup consisting of: hydrogen, methyl, or ethyl; B is attached to anysingle carbon atom along the —(CH₂)_(n)— portion of the alkyl chain; andthe total 2-aryl isomer content of said mixture of overbased alkalineearth sulfonates is between about 8% and about 30% by weight based onthe total weight of all overbased alkylbenzene sulfonates present insaid mixture, and in which the 1-aryl isomer content is less than about3% by weight based on the weight of all isomers of overbasedalkylbenzene sulfonates present, subject to the proviso that the sulfateor sulfonic acid group which is overbased is located at least one of R₁,R₃, and R₅. 40) A composition according to claim 39 in which B ishydrogen for between about 72% and about 98% of all overbasedalkylbenzene sulfonates present, on a molar basis. 41) A compositionaccording to claim 39 in which the amount of 1-aryl isomers present isless than about 0.3% by weight based on the total weight of alloverbased sulfonates present. 42) A composition according to claim 39 inwhich the amount of 1-aryl isomers present is any amount in the range ofbetween about 0.01% to about 0.3% by weight based on the total weight ofall overbased sulfonates present. 43) A concentrate which comprises: a)an alkylbenzene-derived detergent component, said componentcharacterized as comprising any amount between about 10% and about 30%by weight based upon the total weight of the component, of derivativesof at least two different 2-aryl isomers of alkylbenzenes described bythe general formula:

wherein n is equal to any integer between 14 and 28, and in which R₁,R₂, R₃, R₄, and R₅ are each independently selected from the groupconsisting of: hydrogen, a methyl group, an ethyl group, a propyl group,a butyl group, a sulfonic acid group, a sulfonate group, and a sulfonateester group; and b) a base oil. 44) A concentrate according to claim 43in which the content of detergents which are derived from 1-arylalkylbenzene isomers is less than about 0.3% by weight based on thetotal weight of all alkylbenzene-derived detergents present. 45) Aconcentrate according to claim 43 in which the content of detergentswhich are derived from 1-aryl alkylbenzene isomers is any amount betweenabout 0.01% and about 0.03% by weight based on the total weight of allalkylbenzene-derived detergents present. 46) A composition of matteraccording to claim 43 wherein the viscosity of the alkylbenzene mixtureis less than 140 SUS units at 37.8 degrees centigrade. 47) A mixtureaccording to claim 43 wherein the viscosity of the mixture is less than120 SUS units at 37.8 degrees centigrade. 48) A mixture according toclaim 43 wherein the viscosity of the alkylbenzene mixture is less than100 SUS units at 37.8 degrees centigrade. 49) The process of providing ametal surface with a lubricating film comprising the step of contactinga composition according to claim 43 to said metal surface.